According to a new study from University of California Los Angeles researchers, ladies who settled down with Mr. Stable over Mr. Steamy are less likely to be sexually attracted to their partner during their most fertile period than women who paired up with sexually-desirable men.
Not all that surprising, except that in some studies of reproductive survival, women are more attracted to and more likely to mate with stable rather than purely attractive men in an attempt to secure a more lasting environment in which to raise a family.

But in this latest study of heterosexual couples, sexual attraction seems to trump social stability. “A woman evaluates her relationship differently at different times in her cycle, and her evaluation seems to be colored by how sexually attractive she perceives her partner to be,” said senior study author Martie Haselton, a professor of psychology and communication studies at UCLA in a statement.

To assess the changing behavior of women during ovulation, the researchers identified the ovulation cycles of 41 undergraduate women who were in long-term relationships with men. The researchers asked the women to rate the sexual attractiveness of their partners based on questions like, “How desirable do you think women find your partner as a short-term mate or casual sex partner, compared to most men?” The women also answered questions about the sustainability of their mate as a long-term partner.

The women were then asked about the state of their relationship at two different periods during their ovulation cycle: at high fertility just before ovulation and at low fertility. When they were asked about the quality of their relationship, their feelings remained the same, but when they were asked how close they felt to their partner, women with less sexy partners progressively reported diminishing feelings of intimacy and greater aloofness toward their partner as they became more fertile. The opposite was true for women with sexually-desirable partners.

In the second part of the study, the researchers repeated the experiment with 67 new participants. This time, the women were assessed on their “pickiness” by listing how irritating characteristics like moodiness, childishness and thoughtlessness occurred in their partner. Once again, the women paired with less sexy men were most likely to identify the faulty characteristics in their partners as they became more fertile.

Fortunately for the sake of long term relationships, the women’s physical dissatisfaction didn’t last long. According to the researchers, although women may be more critical of their partners during high fertility periods, it doesn’t influence how they feel about their men over the long term.

The authors speculate that women’s changing preferences may stem from an evolutionary benefit attractive men enjoyed long ago. “Since our female ancestors couldn’t directly examine a potential partner’s genetic makeup, they had to base their decisions on physical manifestations of the presence of good genes and the absence of genetic mutations, which might include masculine features such as a deep voice, masculine face, dominant behavior and sexy looks,” said Haselton in the statement.”It is possible that we evolved to feel drawn to these visible markers because, at least in the past, they proved to be indicators of good genes. Ancestral women who were attracted to these features could have produced offspring who were more successful in attracting mates and producing progeny.”

Whether this legacy of assessing mates by physical characteristics continues to provide an evolutionary advantage isn’t as clear; the authors are planning to evaluate that next by studying whether such shifts in women’s opinions of their partners damage their relationships or threaten the stability of their families as time goes on.